AHFS Class:

76:00 Oxytocics

Generic Name

• Oxytocin

Oxytocin is available in 1-mL single-use vials and 10-, 30-, and 50-mL multiple-dose vials.²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸ Each mL contains oxytocin 10 units with chlorobutanol 0.5%.²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸ Acetic acid may have been added to adjust the pH during manufacture.⁴; ²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸

Units

One unit of oxytocin is equivalent to 2 to 2.2 mcg of pure oxytocin.⁴

pH

From 3 to 5.²⁸⁵⁸

Trade Name(s)

Pitocin

Oxytocin is administered by intravenous infusion using an infusion control device;⁴ the drug may also be administered by intramuscular injection,²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸ although intramuscular injection is usually not recommended for induction or augmentation of labor because the drug’s effects are unpredictable and difficult to control.⁴

For intravenous administration, the injection should be diluted to a usual concentration of 10 milliunits/mL by adding 10 units (1 mL) to 1000 mL of Ringer’s injection, lactated, or sodium chloride 0.9%.⁴; ²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸ A higher concentration range of 10 to 40 milliunits/mL in sodium chloride 0.9% or dextrose 5% has been cited for select indications.²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸

Oxytocin injection should be stored at controlled room temperature²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸ and protected from freezing.²⁸⁵⁸ Do not use the solution if it is discolored or contains a precipitate.⁴; ²⁸⁵⁶; ²⁸⁵⁷; ²⁸⁵⁸ Discard unused portions of the drug.²⁸⁵⁷; ²⁸⁵⁸

Oxytocin appears to be rapidly decomposed in the presence of sodium bisulfite.³³³

Filtration

Oxytocin (Parke-Davis) 25 units/100 mL in dextrose 5% and sodium chloride 0.9% was filtered at about 3 mL/min through a 0.22-µm cellulose ester membrane filter (Ivex-2). At this concentration, 25 times higher than normally used, oxytocin appeared to bind initially to the filter from the sodium chloride 0.9% solution. Results in dextrose 5% were equivocal. From these data, it is not possible to draw a definite conclusion regarding substantial binding of oxytocin during normal usage.⁵³³

Standardize 4 Safety

One or more standardized concentrations for this drug have been established through Standardize 4 Safety (S4S), a national patient safety initiative to reduce medication errors, especially during transitions of care. (See Standardize 4 Safety in Users Guide.) Recommendations developed to date through this initiative are available at www.ashp.org/pharmacy-practice/standardize-4-safety-initiative.

Table 1: Standardize 4 Safety Continuous IV Infusion Standard Concentrations for Oxytocin³⁶³⁶

^a See ISMP for best practices. https://www.ismp.org/resources/taking-closer-look-medication-errors-involve-oxytocin; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3956395/

Solution Compatibility

Additive Compatibility

Drugs in Syringe Compatibility

Y-Site Injection Compatibility (1:1 Mixture)

For a list of references cited in the text of this monograph, search the monograph titled References.

ASHP^® Injectable Drug Information^TM. Selected Revisions September 12, 2024. © Copyright, 2024. American Society of Health-System Pharmacists^®, 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.